Is my backlight going out?
The top of my screen is noticeably dimmer now than in the past. "Easy," I thought, "it's the top backlight going out!" But now I'm not so sure. See, whenever the iMac wakes from sleep, the screen is nice and bright for about ¼ second before going back to its now-normal dim state.
Can anyone tell me what's going on? Is my backlight in fact going out, or is something else going wrong? I've checked the brightness control in Displays, and calibrated the screen, with no improvement.